The present invention, in some embodiments thereof, relates to a pump and, more particularly, but not exclusively, to a borehole pump and method of using the same.
The need for shallow aquifer pumping increased dramatically over the past decades. Known in the art are solar pumps of the centrifugal or helical type. Also known are piston pumps, oftentimes referred to in the literature as reciprocating pumps. A conventional reciprocating pump typically uses an externally driven rod that actuates the piston linear stroke motion inside the submersed pump while the rod itself is connected to a crank shaft mechanism or a linear motor above the ground.
Of particular interest is a double action piston pump that pumps the water in both stroke directions, and therefore allows doubling the flow rate for approximately the same input power. U.S. Pat. No. 2,472,647 describes a double action reciprocating pump in which the piston is driven internally by a crank shaft, and U.S. Pat. No. 4,541,787 describes a double action piston pump that is driven by electromagnetic motor.
U.S. Pat. No. 4,778,356 discloses a double action diaphragm type pump with oppositely positioned diaphragm pumping units that are reciprocally operated by a hydraulic cylinder positioned between them. Separate opposite pistons operate the pumping units.
U.S. Published Application No. 20130195702 discloses a pump including a two-stepped cylinder with cavities and a lower intake valve. A hollow plunger is connected to a hollow rod and has a lower discharge valve and a through-hole via which the plunger cavity communicates with a chamber formed as the plunger moves.
Additional background art includes, U.S. Pat. Nos. 5,960,875, 6,015,270, 6,203,288, 7,445,435, European Application No. 1 018 601, and P. Andrada and J. Castro “Solar photovoltaic water pumping system using a new linear actuator” Renewable Energies and Power Quality Journal—RE&PQJ, Vol. 1, No. 5, 2007.